S.D. Codified Laws § 21-40-6
Upon the trial of an action under this chapter, the court shall make its judgment locating and defining the boundary lines involved by reference to well-known, permanent landmarks, if any there be, or if none, then to such landmarks as may be placed or established for that purpose by the surveyor engaged in such work, and if it shall be deemed for the interest of the parties after the entry of judgment, the court may order a registered land surveyor to establish and mark such boundaries. Such landmarks so established, located, and placed in the earth shall have distinctly marked thereon the words, judicial landmark or J. L., with the date that it was so placed and the name or initial letters of the name and the registration number of the surveyor who placed the landmark.
SDCL 21-40-6